Go Back   Team-BHP > Under the Hood > In-Car Entertainment


Reply
 
Thread Tools Search this Thread
Old 28th December 2008, 10:27   #61
Senior - BHPian
 
greenhorn's Avatar
 
Join Date: Apr 2007
Location: TN-14
Posts: 6,837
Thanked: 1,311 Times
Default

just curious, why have you set the HPF and LPF at both amp AND hu?
greenhorn is offline   Reply With Quote
Old 28th December 2008, 11:04   #62
Distinguished - BHPian
 
Technocrat's Avatar
 
Join Date: Feb 2004
Location: Mid West
Posts: 14,896
Thanked: 2,477 Times
Default

Interesting question Greenhorn.

My installer too had put hpf at 80 on my amp but somehow it doesnt seem to cut off frequency very well (or may be I dont feel it as my rear 6X9s are driven by HU) So I need to put HPF on from my HU as well.
Technocrat is offline   Reply With Quote
Old 28th December 2008, 13:04   #63
BHPian
 
dinu2506's Avatar
 
Join Date: Mar 2007
Location: Bangalore
Posts: 788
Thanked: 320 Times
Default

Quote:
Originally Posted by greenhorn View Post
just curious, why have you set the HPF and LPF at both amp AND hu?
Some HU's do not have too much flexibility in terms of setting the X over frequencies, eg lot of HUs have 80Hz as the X over between speakers and sub. Suppose you have components that can go down to 50Hz, this needs finer control eg the amp level.

Last edited by dinu2506 : 28th December 2008 at 13:06.
dinu2506 is offline   Reply With Quote
Old 28th December 2008, 15:17   #64
BHPian
 
rohan_fonseca's Avatar
 
Join Date: Jan 2006
Location: Panaji
Posts: 984
Thanked: 4 Times
Default

Quote:
Originally Posted by dinu2506 View Post
You can lower the HPF at the amp to 63Hz which should take care of this.
Quote:
Originally Posted by greenhorn View Post
just curious, why have you set the HPF and LPF at both amp AND hu?
Its a 444 sony amp and pio 6950. The hpf lpf is fixed at 80hz. However when switched on the lpf doesn't filter too effectively. (on the amp)
Would it be better to just switch off the hpf & lpf on the amp?
rohan_fonseca is offline   Reply With Quote
Old 28th December 2008, 16:54   #65
Senior - BHPian
 
shuvc's Avatar
 
Join Date: May 2005
Location: Kolkata
Posts: 2,895
Thanked: 283 Times
Default

I use a Pio 4950 + JBL 75.4
I normally set the LPF for the sub from the HU. It has 63/80/100/125. I keep the amp setting at around 100hz LPF.
Would it work if I set the amp to, say 40hz HPF for the sub? And the HU at 80hz LPF? This should ensure the sub will only play 40-80hz?
shuvc is offline   Reply With Quote
Old 28th December 2008, 20:25   #66
BHPian
 
dinu2506's Avatar
 
Join Date: Mar 2007
Location: Bangalore
Posts: 788
Thanked: 320 Times
Default

Quote:
Originally Posted by shuvc View Post
I use a Pio 4950 + JBL 75.4
I normally set the LPF for the sub from the HU. It has 63/80/100/125. I keep the amp setting at around 100hz LPF.
Would it work if I set the amp to, say 40hz HPF for the sub? And the HU at 80hz LPF? This should ensure the sub will only play 40-80hz?
The sub should be able to handle down to 25Hz. Why do you want to lose the 25-40Hz range?
dinu2506 is offline   Reply With Quote
Old 28th December 2008, 21:27   #67
Team-BHP Support
 
navin's Avatar
 
Join Date: Mar 2004
Location: mumbai
Posts: 22,502
Thanked: 3,880 Times
Default

Quote:
Originally Posted by rohan_fonseca View Post
Will this result in missing frequencies?
Quote:
Originally Posted by dinu2506 View Post
I guess you will lose the 63Hz to 80Hz range.
yes and no. it your slopes are 12db butterworth you may not suffer any loss, if your slopes ar L-R you will have just a 1-2db drop peaking somewhere around 70Hz. so relax. if it sounds good to you leave it alone.
navin is offline   Reply With Quote
Old 28th December 2008, 21:29   #68
Team-BHP Support
 
navin's Avatar
 
Join Date: Mar 2004
Location: mumbai
Posts: 22,502
Thanked: 3,880 Times
Default

Quote:
Originally Posted by dinu2506 View Post
The sub should be able to handle down to 25Hz. Why do you want to lose the 25-40Hz range?
1. the ear is not very sensitive at 25Hz so you need a lot of power to hear it
2. lot of music has no real information at 25-30Hz by filtering this range out your sub can concentrate on the area above 40Hz and play louder as it's excursion limits will not be as highly taxed.
navin is offline   Reply With Quote
Old 29th December 2008, 01:01   #69
Senior - BHPian
 
shuvc's Avatar
 
Join Date: May 2005
Location: Kolkata
Posts: 2,895
Thanked: 283 Times
Default

Quote:
Originally Posted by navin View Post
1. the ear is not very sensitive at 25Hz so you need a lot of power to hear it
2. lot of music has no real information at 25-30Hz by filtering this range out your sub can concentrate on the area above 40Hz and play louder as it's excursion limits will not be as highly taxed.
Thanks. That's the reason I want to do it. So it's doable then. Will try this out tomorrow.
I understand I should play it by the ear, but theoretically what should I use as the lower cut-off? I normally do not listen to trance/house/metal/hiphop/classical. Is 40hz an ok cutoff for music?
shuvc is offline   Reply With Quote
Old 29th December 2008, 11:02   #70
Team-BHP Support
 
navin's Avatar
 
Join Date: Mar 2004
Location: mumbai
Posts: 22,502
Thanked: 3,880 Times
Default

Quote:
Originally Posted by shuvc View Post
Is 40hz an ok cutoff for music?
42Hz is the low E on a bass guitar.
navin is offline   Reply With Quote
Old 29th December 2008, 11:49   #71
BHPian
 
drvhplyevraftr's Avatar
 
Join Date: Sep 2008
Location: Hyderabad
Posts: 306
Thanked: 16 Times
Default

This is what I have done so far and it sounds pretty good to me.

My setup:
Boston components on the front and Boston co-axials on the rear.

The front and rear speakers are powered by JBL 75.4

The JBL GT5-12 sub is powered by JBL 3501 monoblock.

The HU is JVC AVX 44.

On the HU, I have set the HPF to Through.
On the JBL 75.4 AMP set the HPF for front and rear
and set the frequency at about 60 Hz.

On the HU, set the LPF at 120 Hz.
On the JBL 3501 monoblock, set the LPF at about 80 Hz
and the HPF to off (I think at OFF it is about 10 Hz).

While I am happy about the sound from front and rear
speakers, I am not sure if I am utilizing the sub optimally.

Please let me know if there is anything that I need to change
on the LPF on the HU, LPF/HPF on the JBL 3501 monoblock so that
I can use the sub to its true potential. In otherwords with
the current settings am I losing out some frequencies that can
be played on the sub. I am happy with the front/rear speakers
and the JBL 75.4 settings so I will not be changing those
settings. I need help and advice only on the LPF settings on
the HU and the LPF/HPF settings on the monoblock.

Thank you.
drvhplyevraftr is offline   Reply With Quote
Old 29th December 2008, 12:20   #72
BHPian
 
dinu2506's Avatar
 
Join Date: Mar 2007
Location: Bangalore
Posts: 788
Thanked: 320 Times
Default

Quote:
Originally Posted by drvhplyevraftr View Post
On the JBL 75.4 AMP set the HPF for front and rear
and set the frequency at about 60 Hz.

On the JBL 3501 monoblock, set the LPF at about 80 Hz
Can you put in pictures of the dials so that I can know how you set 60Hz on the 75.4 and 80Hz on the 3501. The dial only shows a min of 32Hz and max of 320Hz with no markings in between and I understand it is not a linear scale. As far as I know the dot (at the 10'O Clock position) in 75.4 is 50Hz and the dot in 3501 (at the 2 'O Clock position) is 80Hz.
dinu2506 is offline   Reply With Quote
Old 29th December 2008, 12:50   #73
BHPian
 
drvhplyevraftr's Avatar
 
Join Date: Sep 2008
Location: Hyderabad
Posts: 306
Thanked: 16 Times
Default

Well since you asked, here is the procedure that I followed:

I was given a 50 and 80 Hz tone (by some one from another forum).

I disconnected the RCAs to the sub, rear speakers and played the
50 Hz tone (The RCAs for the front speakers are only connected).

Turn the volume to about 2/3rds the max HU volume and turn the
freq on the 75.4 amp to 32 hz. You can feel there is a hum/vibration
coming from the front speakers. Now turn the frequency clockwise
until the low hum/vibrations disappear. It sets it to about 50 Hz,
I turned it a little bit further to get to around 60 Hz.

Followed the same procedure for the rear speakers.

I then disconnected the front and rear speakers and connected the
sub RCAs. I played the 80 Hz. Set the HU LPF to 120 Hz. Turned the
LPF frequency on the sub amp to 320 Hz. Turn the frequency knob
anti-clock wise until you can hear the hum coming from the sub.
This should set the sub amp frequency to about 80 Hz.

Now this is the procedure that was given to me by some one else
from a different forum and please dont ridicule me or this
procedure.
drvhplyevraftr is offline   Reply With Quote
Old 29th December 2008, 16:38   #74
BHPian
 
dinu2506's Avatar
 
Join Date: Mar 2007
Location: Bangalore
Posts: 788
Thanked: 320 Times
Default

If possible, please upload the closeup pictures of the settings so that we can have a reference. This will help lot of JBL users.
dinu2506 is offline   Reply With Quote
Old 29th December 2008, 17:00   #75
Senior - BHPian
 
Bass&Trouble's Avatar
 
Join Date: Mar 2006
Location: Bombay
Posts: 2,744
Thanked: 71 Times
Default

Quote:
Originally Posted by drvhplyevraftr View Post
I disconnected the RCAs to the sub, rear speakers and played the
50 Hz tone (The RCAs for the front speakers are only connected).
Now turn the frequency clockwise
until the low hum/vibrations disappear. It sets it to about 50 Hz,
By turning up the crossover dial to a point where the 50Hz tone is not audible any more, you have set the crossover to a frequency way higher than 50 Hz.
Bass&Trouble is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Frequency range chart in reference to Various Musical Instruments pranava999 In-Car Entertainment 3 16th April 2010 21:25
Radio Frequency Car Keys Not Perfect mithun Technical Stuff 24 13th August 2009 15:57
What is resonance (tuned) frequency? m2avg In-Car Entertainment 18 30th November 2008 10:06
Are low frequency sounds hazardous to kids satish_appasani In-Car Entertainment 28 9th October 2006 10:56


All times are GMT +5.5. The time now is 21:31.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks